In many fields of technology, for example transportation systems and road traffic planning, there is a desire to obtain information related to a number of individuals who are travelling along a specified route. Such information can be of assistance for example during design of public transportation systems, for dimensioning traffic routes and for coordinating bus and train schedules, and also for obtaining statistic information regarding trends and changes related to people's travel behavior. In particular, such information can be vital for planning and evaluating transport systems.
In particular, there is a need for reliable information related to the number of passengers travelling on vehicles such as buses and trains forming part of a public transportation system. In this manner, passenger traffic can be analyzed by counting the number of passengers travelling on different routes.
The above-mentioned problem can be solved manually by counting travelers on buses, trains and other means of public transportation. However, a manual method requires staff which is assigned to the task of actually counting the travellers. Consequently, such a method is expensive and complicated to implement.
Another solution to the above-mentioned problem is to utilize a mechanical turnstile which is arranged so that individuals can pass through. Every turn on the turnstile can then be registered as a count of a person passing. Such a solution is reliable but slow and ineffective, and also requires mechanical equipment in the form of such a turnstile. Another disadvantage is that the count of individuals may only occur at one single predetermined place, i.e. where the turnstile is located.
A further solution is to use suitable sensors for detecting passages of individuals, for example sensors based on infrared technology. However, such a sensor-based solution is technically complex and difficult to implement. It also requires a relatively high amount of hardware, i.e. sensors, communication devices, evaluation and control units.
Yet another solution is to use video cameras which are connected to automatic image recognition systems, which in turn are arranged so as to count the number of passing persons. However, in some countries it can be expected that detection of individuals by means of video cameras can be considered as violating the personal integrity.
Consequently, in the relevant fields of technology there is a continuing need to provide simple, accurate and cost-effective solutions for detecting a number of individuals moving or travelling on a given route, either travelling in vehicles or by foot.